Achieving Self-Stiffening and Laser Healing by Interconnecting Graphene Oxide Sheets with Amine-Functionalized Ovalbumin

Mimicking the remarkable properties of natural materials such as toughness, self-stiffening, self-healing, etc., is useful for several structural, functional, and biomedical applications. The judicious combination of natural and synthetic building blocks to design hybrid materials could offer an alternative route to achieving the aforementioned properties of natural materials. This study reports easily scalable process to synthesize graphene oxide (GO)/egg white hybrid material (polyalbumene) by cross-linking GO nanosheet with the amine-based cross-linker diethylenetriamine (DETA) and egg white. The result is a layered material like nacre, exhibiting high strength and toughness. Abundant functional groups on the GO allow covalent interactions between DETA and egg white protein amino acids. The atomistic simulations reveal that the insertion of GO into the composite has a sizeable impact on the composite's stiffness. As shown by experiments, the hybrid material has an elastic modulus of ≈41 MPa and a ductility of more than 25%. The hybrid material also exhibits a fracture repair property under laser exposure as well as CO<inf>2</inf> absorption and stiffening over time, suggesting an adaptable behavior. This work explores the possibility that the combination of synthetic and natural approaches offers a better route to designing advanced, tough, strong, adaptable, and fracture recovering materials.